Re: [HACKERS] GSoC 2017: weekly progress reports (week 6)

> 12 марта 2018 г., в 1:54, Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> написал(а):
>
> On Wed, Mar 7, 2018 at 8:30 PM, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> wrote:
> I suggest to create a new function GinPredicateLockPage() that checks
> whether fast update is enabled for the index. The current arrangement
> looks too repetitive and it seems easy to make a mistake.
>
> BTW, should we also skip CheckForSerializableConflictIn() when
> fast update is enabled? AFAICS, now it doesn't cause any errors or
> false positives, but makes useless load. Is it correct?
>
BTW to BTW. I think we should check pending list size with GinGetPendingListCleanupSize() here
+
+ /*
+ * If fast update is enabled, we acquire a predicate lock on the entire
+ * relation as fast update postpones the insertion of tuples into index
+ * structure due to which we can't detect rw conflicts.
+ */
+ if (GinGetUseFastUpdate(ginstate->index))
+ PredicateLockRelation(ginstate->index, snapshot);

Because we can alter alter index set (fastupdate = off), but there still will be pending list.

We were discussing this with Shubham back in July, chosen some approach that seemed better, but I can't remember what was that...

Best regards, Andrey Borodin.